Boolean search strings for chemical engineers: refining, specialty chemicals, pharma and semiconductors, process safety and the PE

A chemical engineer search works when it names the industry, because the degree spreads across very different jobs: refinery and petrochemical unit engineers, specialty chemical plant engineers, process design engineers at engineering firms, pharmaceutical and biotech process development engineers, and semiconductor process engineers. Each writes its own words, and few move freely between them. The title "process engineer" is shared with every one of them, and "chemical" pulls in chemists, sales reps and even chemical dependency counselors. When the client cares about the title more than the degree, our Boolean search strings for process engineers cover semiconductor, discrete manufacturing and biopharma process work. As of November 2026, the strongest blocks are the industry, the unit or process work, and the process safety terms that come from running a plant.

Below are ten strings by industry and kind of chemical engineering work, and what LinkedIn, Indeed and Google support as of November 2026. For the engineers who design the equipment, see Boolean search strings for mechanical engineers; for discrete-parts plants, see Boolean search strings for manufacturing engineers.

Industries, safety rules and credentials that change what a chemical engineer search finds

• Where they work. The BLS page for chemical engineers says they apply chemistry, physics and engineering to design equipment and processes for products such as gasoline, detergents and paper, and that chemical manufacturing employed 28 percent of the about 21,900 jobs in 2025, followed by engineering services at 11 percent and research and development at 9 percent, as of November 2026.
• Process safety is a rule, not a skill word. OSHA's Process Safety Management page says 29 CFR 1910.119 contains requirements for managing the hazards of processes that use highly hazardous chemicals, and EPA's Risk Management Program page says facilities that use extremely hazardous substances must develop a Risk Management Plan and resubmit it every five years. Engineers who support those plants write PHA, HAZOP, MOC and PSSR.
• CCPSC. AIChE's Center for Chemical Process Safety runs the CCPSC, its Certified Process Safety Professional designation. Its page says it is a certification process rather than a training program, that an annual renewal with continuing education keeps it current, and that a CCPSC search tool is available, as of November 2026.
• The PE is optional for most roles. The BLS page says licensure is not required for entry-level chemical engineers. NCEES says its PE Chemical exam is computer-based, given year-round and designed for engineers with at least four years of post-college work experience. The license itself comes from a state board; NCEES keeps a licensing board directory for the lookup.
• Pharma words differ from device words. Process development engineers in biotech write upstream, downstream, cell culture and tech transfer; they rarely write the device standards a quality engineer uses. For quality roles in regulated plants, see Boolean search strings for quality engineers.

Ten Boolean strings by industry and kind of chemical engineering work

Swap in the industry, process and metro from your own intake; these are examples. Search on the work and the credentials, never on a term that stands in for age, sex, race, religion, national origin, disability or veteran status.

Refining, chemicals and process safety

1. Refinery process or unit engineer — LinkedIn Recruiter, Job titles + Keywords filters
("process engineer" OR "chemical engineer" OR "unit engineer") AND (refinery OR refining OR petrochemical) AND ("aspen hysys" OR hysys OR "unit monitoring" OR turnaround) NOT ("business process" OR "process improvement analyst")

2. Process safety engineer — LinkedIn general search
("process safety engineer" OR "psm engineer" OR "process safety") AND (hazop OR "process hazard analysis" OR "management of change") AND ("1910.119" OR psm OR "risk management program") NOT ("safety officer" OR "ehs coordinator")

3. Chemical plant process engineer — Indeed Smart Sourcing
("process engineer" OR "chemical engineer" OR "production engineer") AND skill: ("batch reactors" OR distillation OR "heat exchangers" OR "mass balance") AND fieldofstudy: "chemical engineering" NOT (chemist OR "lab technician")

Design, simulation and licensure

4. Process design engineer at an engineering firm — LinkedIn general search
("process design engineer" OR "process engineer" OR "chemical engineer") AND ("p&id" OR "p&ids" OR pfd OR "heat and material balance") AND (epc OR "front-end engineering design" OR "detailed design")

5. Process simulation engineer — LinkedIn Recruiter, Keywords filter
("process engineer" OR "chemical engineer" OR "process simulation engineer") AND ("aspen plus" OR "aspen hysys" OR chemcad OR "pro/ii") AND (simulation OR "process modeling")

6. Licensed chemical engineer — LinkedIn general search
("chemical engineer" OR "process engineer") AND ("professional engineer" OR "pe license" OR "licensed pe") AND ("process design" OR "relief valve" OR "pressure relief")

Pharma, semiconductors and X-ray

7. Bioprocess or process development engineer — LinkedIn general search
("bioprocess engineer" OR "process development engineer" OR "process engineer") AND ("cell culture" OR fermentation OR chromatography OR "downstream processing") AND (cgmp OR "tech transfer" OR "scale-up") NOT ("clinical research" OR "medical science liaison")

8. Semiconductor process engineer — LinkedIn general search
("process engineer" OR "etch engineer" OR "thin films engineer") AND (etch OR cvd OR "atomic layer deposition" OR "chemical mechanical") AND (fab OR wafer OR semiconductor) NOT (sales OR "field service")

9. Public profiles by tool and metro — Google X-ray
site:linkedin.com/in "chemical engineer" "aspen plus" "baton rouge" -jobs -recruiter -chemist

10. Recent public resumes with process safety work — Google X-ray, filetype and date search
filetype:pdf "chemical engineering" resume "process engineer" "hazop" after:2025-01-01 -template -sample

What LinkedIn, Indeed and Google actually support

LinkedIn's Boolean help page requires capital AND, OR and NOT, supports quotes and parentheses, evaluates quotes first, then parentheses, NOT, AND and OR, and does not support wildcards, as of November 2026, so "aspen hysys" and hysys, or "p&id" and "p&ids," go in side by side. It does not say how symbols such as & and / are matched, so test "p&id" and "pro/ii" before relying on them. LinkedIn Recruiter's Boolean page lists "and" and "of" among the stop words ignored in Keywords, which can loosen "heat and material balance" and "management of change," so use those phrases in the general search or pair them with PFD and MOC.

Indeed's repair and maintenance guide documents the skill: and fieldofstudy: fields, and fieldofstudy: "chemical engineering" is the cleanest way to keep chemists out of a plant search. Google's search operators page documents quotes, site:, the minus sign, filetype: and the before: and after: date operators, but not OR, so strings 9 and 10 use none.

Narrowing by industry, stage and site work

The industry is usually the must-have. A refinery client rarely takes a biotech process engineer, and a semiconductor fab rarely takes a refinery one, because the units, chemistry and regulations differ. Then ask the stage: research and process development, scale-up and tech transfer, operations support on a running unit, or design at an engineering firm. Operations roles often carry turnaround schedules, call-outs and site work in protective equipment, which is not searchable; raise it on the first call.

Seniority shows in ownership: "owned the unit," "led the HAZOP," "MOC approver," "led the startup" and "scaled from pilot to commercial," against "supported" and "assisted." LinkedIn's premium search filters page says Years of Experience and Seniority Level are only in Recruiter and Sales Navigator. For process safety leaders, the 30-60-90 day plan for safety managers shows what that seat owns.

False positives worth excluding with NOT

• Chemists and lab technicians. Analytical and research chemists write chemistry, chemicals and process all day. Exclude chemist and "lab technician," or require fieldofstudy: "chemical engineering" on Indeed.
• Chemical dependency counselors. Addiction-treatment profiles use "chemical dependency." Exclude the phrase whenever "chemical" stands alone in a string.
• Business process engineers. Banking, insurance and IT staff write "process engineer," "process improvement" and "process excellence." Exclude "business process" and require plant words.
• Operators and process technicians. Chemical operators and refinery operators list the same units at the operating level. Exclude operator and "process technician" for engineering roles.
• Chemical sales and technical service. Distributor and supplier reps list every chemistry. Exclude sales and "account manager," and ask whether a technical service engineer counts.
• Safety staff who are not engineers. EHS coordinators write PSM and HAZOP at the compliance level. Exclude "ehs coordinator" and "safety officer" for process safety engineer roles.
• Academics, for plant roles. Professors and postdocs write the same chemistry. Exclude professor and postdoc unless the client wants research depth.

A worked example: three passes on a specialty chemicals search

An invented search, shown as it actually gets narrowed.

The degree block removed the chemists; the process safety block found the engineers who work on a live plant. Add the safety block once the industry block has done its work.

What a search cannot verify

A string can find someone who names the right industry, tools and safety terms. It cannot show whether they led the HAZOP or took notes in it, whether a scale-up they mention reached commercial production, or whether a PE license is active. Confirm licenses with the state board and CCPSC with AIChE's search tool, then use the interview questions for safety mindset on the call and the interview guide for manufacturing roles for the plant loop.